Aishwarya Rai is keeps gaining and loosing weight for her coming films. First, Many Ratnam asked her to gain weight for the film 'Guru'. Then Sanjay Gandvi asked her to shed those same kilos for 'Dhoom 2'. So, ash called her personal trainer Deepika Mehta in Namibia. Aishwarya wakes up at 4 am everyday and undergoes a two-hour workout regimen. After that she heads to the location for shooting. A source says, "She has been working 16 hours a day for the film and is exhausted by the end of the day."